1. Field of the Invention
The present invention relates to a process for reducing the content of triglycerides in egg yolk and in products containing egg yolk.
2. The Prior Art
Since an association between a triglyceride-rich diet and a number of symptoms and medical disorders is taken to be confirmed, a possible way to prevent a number of medical disorders is to decrease the daily supply of these substances by reducing the triglyceride content in foods.
An important constituent of many foods which, moreover, is extremely rich in triglycerides, is egg yolk. The majority of these triglycerides is present in the form of mixed glycerol esters of saturated (approximately 30 to 35% by weight) and monounsaturated fatty acids (45% by weight). It is therefore desirable to reduce the triglyceride content of the egg yolk, in particular the content of glycerol esters containing saturated fatty acids.
A number of processes are known for reducing the triglyceride content in egg yolk. All these processes use organic solvents for reducing the triglyceride content.
The following processes may be mentioned by way of example.
The reduction of the triglyceride content using nonpolar solvents such as pentane, hexane or ether is disclosed by DE-A-3,429,703. A reduction of the triglyceride content by 80% to 95% is achieved.
Reduction of the triglyceride content using dichloroethylene is disclosed by U.S. Pat. No. 3,607,304.
The known processes have the disadvantage that a large number of technical resources are required to carry them out. Thus, handling solvents requires particular technical measures such as explosion prevention measures.
Furthermore, there is always the risk with these processes that solvent residues hazardous to health remain. Thus, chlorinated solvents, because of possible adverse effects on health, should as far as possible no longer be used at all.
In order to remove the solvents as completely as possible, elevated temperatures are required. These can lead to changes in the food, for example, of a taste or nutritional type of change.
It is a further disadvantage that the known extraction techniques are unselective, i.e., when they are employed, essential nutrient constituents are also always separated off.